During the summer, a series of operas is put on in the theatre at Drottningholm. The 18th century theatre is special also because it was unused for many years, and rediscovered only in the latter part of the 20th century. Almost all of the equipment is original, and the stage is unusual for having a significantly greater depth than width. The operas are performed by musicians wearing period costume, and the orchestra performs using period or copies of authentic instruments. The stage effects include a wave machine, thunder machine, and a flying chair which is often used for deus ex machina effects. Most productions demonstrate some of the effects possible using the original equipment. Because of the possible fire hazard in the wooden building, the theatre uses electric lights, designed to flicker like candles.